The present invention relates to new molecules for the treatment and diagnosis of tumors. The invention furthermore relates to therapeutical compositions comprising one or more of these molecules and to the use of both in treatment and diagnosis of cancer.
The diagnosis and therapy of cancer still requires a large input from the pharmaceutical and chemical industry. Although a substantial effort is made to develop new treatments, there are still many tumor types for which no treatment exists. An additional problem is the formation of micrometastascs, which cannot be diagnosed or treated.
An important problem in treatment is the similarity between normal cells and cancer cells. Treatments interfering with the growth of tumor cells will also interfere in the growth of healthy cells. Radiotherapy as it is now known consists essentially of an arbitrary cross-fire from outside the cell or the cytoplasm. Because this is a rather rough treatment surrounding cells and tissues might also be damaged leading to more or less severe side effects.
The provision of an improved radiotherapy and diagnostic method for cancer which uses very low amounts of radionuclides and leads to a direct treatment in the malignant cell is therefore highly desirable.
It is known that the metabolism of cancer cells differs from that of normal cells. In addition, cancer cells appear to have an increased membrane permeability in comparison to normal cells due to an increased expression of membrane receptors. The result is that the cancer cells are more permeable for biological vectors, like proteins and peptides.
The enhanced uptake of such biological vectors can be used in the diagnosis of tumors by binding a radionuclide to a protein, for example by iodination of tyrosine functions in the protein or by covalent coupling of radioactive metal complexes. These molecules combine a tumor seeking function and a radioactive function. Although these types of molecules have been used for diagnosis, their use in therapy was not yet described.